We have our body parts to work.We can perform works with our "Karmendriyas".The "Karmendriyas" are those "indriyas" with which we can perform work.Suppose you are doing exercise.It is a work.Due to this ork your body gets relief,health increase,power increases and you live a longer life.These are the effects of your work.You are able to see that this work is having good effects.So this you call as "Good work".

Suppose you drink wine.Because of this work you will fall ill.So its effect is coming out to be bad.This you will call as "Bad work".

You loot someone and take his money.Its effect is both good and bad.The good effect is that you become reach but the bad effect is that others become poor.So some works have both good and bad effects.But if you put one drop of poison in ambrosia then the complete ambrosia becomes bad for you.So even if there is one bad effect your complete work is called as "Bad work".

So Good work=everyone get benefits Bad work=even one get hurt

In order to know which is good work and which is bad we will have to know about the side effects of our work.In order to know the effects of a work one must have knowledge.So to become a good person we should be having knowledge.Without knowledge we cannot become good.